Well bore photography



Sept. 27, 1960 R. B. ROSENE ETAL 2,953,979

WELL. BORE PHOTOGRAPHY Filed April 4, 1957 Cable for camera and light Earl/7 '5 surface I with E arr/7 Well bare Slug af transparenf, heavier Man wafer, oil and wafer insoluble liquid medium Camera with light source Object to be ph afograph ed INVENTORS! Raberf B. Rasene Ja/m E Eberhard mmam ATTORNEYS 2,953,979 Patented Sept. 27, 1960 WELL BORE PHOTOGRAPHY Robert B. Rosene and John F. Eberhard, Tulsa, Okla., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware Filed Apr. 4, 1957, Ser. No. 650,587

6 Claims. (Cl. 95-11) This invention has reference to an improved technique for photographing by various means the walls and other subterraneal surfaces of and within wells and the-like borings that penetrate into the earths surface.

It has been proposed and is known to visually examine for various purposes the interior of bore holes into the earths surface through the agency of photography Such practice in openings of the type that prohibit human access greatly aids the study of subsurface formational characteristics and permits other desirable introspection to be accomplished. In oil or gas wells, for example, it also affords an easy means for examining, in 'situ, the interiors of easing strings and-the like installations, and

viewing tools and herinstmmems that bllost liquid condensation product,rhaving-a specific gravity in the hole. v As the procedure is conventionally practiced, the particular photographing device that is employed is immersed within the hole in various naturally-occurring of specially? provided water (including salt water) or oil media through which the well bore photography must usually be accomplished. Although optical-uansparency is'an obviously significant desideration for. such, media to possess, it may oftentimes be a difiicultcondition to achieve and maintain. This is particularly the case when pictures and other visualizations are being, taken and made in oil Wells. Thus, to mention typica-l'vexations that may occur, aqueous media may become cloudy and opaque from black sulfide water or other contaminants such as drilling muds and otherfluids that are already present in the Wells. Dark crude oils may likewise affect an oil medium. h It would be advantageous to provide an improved technique for well bore photography that would not be subject to the serious drawbacks and deficiencies that have prevailed. The attainment and realization of this and corollary ends as will be manifest in the, ensuing description and specification are among the maior objectives of thepresent invention.

Accordingly, photography in well bores and the like openings in the earths surface may be performed in an eminently suitable manner by practiceof the present invention which comprehends providing at a desired point in a well or the like boring into the earths surfacethat is desired to be photographed a slug of. an oil and water immiscible and insoluble transparent liquid having a specific gravity greater than that of water; said liquid slug being provided in an adequate and sufficient volume to fill a portion of said boring at the point that is desired to be photographed so as to encompass said point with said liquid; immersing in said liquid medium both alight source for illuminating the object to be photographed 'and an underliquid operable photographing device or dium. Practice of the technique of the present invention reli-. ably possibilitates. the accomplishment of clear legible photographs and other visual reproductions in which the. surfaces or other objects in the borings that are desired! to be visually examined are plainly discernible, As is:

. apparent, and as has been indicated, both wall and bot-.

tom hole surfaces may advantageously be photographed,

as may other objects and installations in the borehole. And, quite advantageously in some cases scanninglon panoramic viewing procedures (eitherlongitudinally of circumferentially, or both, of all or any desired portion of the bore) may beobserved to provide integrated sequential series of photographs or image reproductions of larger areas of the bore surface that can be encom f passed in or with a single, stationary photographi c view 1 The presence of black sulfide water, dark crude oil, drill-I ing rnuds or the like light-occluding contaminants does not hamper the intended photographic accomplishment. In .Figure l. or the ,hereto annexed drawing there is a schematic representation that portrays the present invention. *In the illustration, the dimensional proportions:

.stituent thatis utilized in'the syrupy liquid resinous-conmeans; and photographing through said transparent liquid ;medium the desired point or object at said point in said have been distorted for purposes of clarity. The transparent liquid-mediumthat is employed-with such great benefit 'in the practice of the presentinven-z tion may advantageously be an oil and water insoluble between-about 1.2 and 2, of fromzabout 0.75 to 4 moles of formaldehyde with each unimolar proportion ofia. phenolic constituent selected from the group consisting of mixtures of tribromophenoland the common, trifunc tional phenol, C H OH, that, expediently, containfmole fractions of the latterbetween about 5 and percent; monoand dibromophenols that, optionally, may contain minor proportions (as, say, mole fractions that. are uplto about .10 percent) of the common phenol; mono-,.di-,.a.11d trichlorophenol that, optionally, may contain minor pro? portions,-on the same basis as above, of the common phe nol; and mixtures thereof More advantageously,.-.the liquid condensation products that are employed; contain aboutwl to 1.5 moles of formaldehyde .to. each moleof the phenolic constituent.that ispresent therein and .have

encountered in the usual wells and other borings that may 7 be. made into the earthfs surface. This facilitates their satisfactory positioning andrnaintenance, in a readymanner, at desired points or levels in. theboreholer They also have suitablethermal stability for the intended application. And, in addition, .theyare generally obtainableas pellucid, syrupy liquids that are well adapted .to transmit light and function as a photographic medium. Furthermore, they ordinarily remain in this condition for sufliciently'long periods of timeafter their preparationto enable their practical utilization. e The ratio of the formaldehyde to the phenolic condensation products is of great. importance and mustbe critically observed in orderto achieve. the desired results, When less than the minimumproportionof-the aldehyde is employed, the molecular weight 10f the resinous product is generally found to be so low. 551w render it difficult to obtain liquid products having the desired gravity. When proportions of formaldehyde ar e boring that is encompassed by and with saidjliquidme g 3. mployed that exceed the maximum mentioned propor- .ons, the resin product assumes such a marked increase a reactivity that it tends to cross-link to a sulticient exent to form a solid. While it is highly advantageous or the phenolic constituent to be comprised of mixtures if tribromophenol with the common phenol, suitable iquid resinscan also be obtained with other of the menioned phenolics. In this connection, the specific gravity f the liquid resin product can be altered and varied by hoice and change in proportion of the various phenolic .onstituents (having different individual gravities) that nay be employed therein. This is particularly the case vhen the amount of common phenol that is condensed n the resin is varied. Greater amounts of the common vhenol ordinarily reduce the specific gravity of the liquid esin product.

The condensation products can be readily prepared n a known manner by reacting the phenolic constituent with formaldehyde or paraformaldehyde to the point Where a syrupy liquid product having the desired characteristics is formed. Ordinarily, this may be accomplished under basic catalysis using alkali metal hydroxides or carbonates for this purpose. Generally, from about 0.01 to 0.6 and preferably from 0.012 to 0.3 inole of the basic catalyst are employed per mole of the phenolic constituent being condensed. The condensation reaction, which is best accomplished at an elevated temperature, say in the neighborhood of l70200 F., may be terminated at a desired point by acidification to neutralize the catalyst with hydrochloric, formic or other suitable acid materials. When tribromophenol is being condensed, however, it is not ordinarily necessary to employ an acid neutralizer for terminating the reaction since the hydrogen bromide that evolves during the condensation effectively serves this purpose.

The transparent liquid medium is placed at the bottom of the well bore or other desired point to be photographed by means of liquid displacement techniques that are common to, and frequently practice in connection with well operations. Thus, for example, in a well that may contain casing or tubing and which may be filled with either water, brine, crude oil or drilling mud, the liquid may be spotted at any desired point or level in the bore hole by positioning the end of a tubing, for example, at the desired point; pumping the slug of liquid by means of positive displacement apparatus down the tubing wherein it is displaced downwardly as a distinct layer to the point of discharge from the tubing; then discontinuing the pumping when the slug of liquid has arrived at the desired point or level. During the injection of the liquid medium through the tubing into the well bore, an equivalent volume of well fluid is withdrawn from the casing. This sort of procedure is known conventionally in the trade as circulating a well. It and similar or analogous techniques are well adapted for locating the slug of liquid medium that is employed in the practice of the invention. As mentioned, the volume of the liquid medium that is used for the slug should be large enough to fill the bore hole and encompass the subject desired to be visually reproduced at the point in the bore hole where the photography is to be undertaken.

In the cases where it may be necessary to spot the liquid medium at a point in the boring above its bottom, it may oftentimes be advantageous to employ a temporary plugging material such as gellable aqueous solutions of various natural and synthetic gums, aluminum soap gel or other non-penetrating liquids which may contain fine particulate filler ingredients just below the desired location of the medium. The heavy liquid medium may then be stationarily positioned over the plug. Of course, in the event that the liquid resin should solidify during its residence in a Well, it can easily be removed and the well reopened by reboring operations.

Liquid media of the indicated formaldehyde condensed phenolic constituent variety may genermly be employed and spotted at desired points which occur in bore holes at levels as deep as 20,000 feet since, in many wells, the average temperature at such depths is not in excess of about 400 F. It may be prudent to forego the practice of the invention with such phenolic liquid resin media, however, when the point or object to be photographed is situated in a location having an average temperature that is much in excess of about 400 F. Such elevated temperatures may harden, solidify, degrade or disintegrate the phenolic liquid resin and thus minimize or nullify the benefit of its use in the practice of the -invention. In connection with this, care should be taken when employing photographic film in well locations having high average temperatures to use heat-resisting varieties of film or to employ cooling means in the camera or to avoid keeping the camera exposed to they high temperatures for such periods of time as might allow its internal temperature to rise to that of the well. Such means may preclude the possibility of break-down of the film.

After its introduction and spotting in the well bore, the light source and photographic device or means are lowered into the well bore and immersed in the liquid medium to enable the pictures or other visual reproductions to be made. Of course, both the light and the camera are trained in the best possible manner on the object or surface to be photographed. In some cases, it may be necessary to remove tubing or other installations from a well before introducing the photographic apparatus down the bore hole; this being governed by the demands of the occasion. Practically any incandescent or other light source that is capable of use in liquid submersion and which may be integral with or separate from the camera assembly may be utilized for illumination when photographic pictures are being taken in the practice of the invention. The photographic means that is employed, as has been indicated, must be of the underliquid variety that is adapted to operate while submerged in a liquid medium. Suitable camera apparatus may be similar to or analogous with that which has been described by E. M. Barstow and C. M. Bryant in their article on a Deep-Well Camera which appeared at page 74 in the March 15, 1947 issue of The Oil and Gas Journal. When photographic cameras are utilized in the practice of the invention it is generally advantageous to employ a photographic film of the infrared light sensitive variety which is adapted to record images flooded by light having a wave length in the range from about 6700 to 8700 Angstrom units. This type of light which is substantially out of the visible spectrum may be considered to be in the near infra-red range. This accommodates employing suitably short exposures in the taking of the pictures, especially when the described species of condensation resins are employed which have relatively poor light transmitting characteristics in the visible range but afford good transmission of light in the near infra-red range. If desired, the photographic device may alternatively be a television camera for photographing the desired objects and electronically transmitting the pattern to cooperating surface apparatus and means for visual reproduction. Television devices for such purposes may be built and employed in a generally similar manner to the referred-to type of photographic camera equipment, taking the necessarily diverse structural and functional design requirements into account. When televising cameras are employed, it is advantageous to utilize especially intense light sources for illumination in the well bore.

By way of further illustration, several suitable liquid media were prepared by condensing various phenolic constituents with formaldehyde using various molar proportions of the reactant ingredients. In each case, the

passed at which the parafiormaldehyde dissolves. This is necessary to obtain transparency in the liquid resin product. The cooking of each batch was continued until a drop of the reaction mass was insoluble in kerosene, a condition that was generally obtained after a total cooking period of 20-25 minutes. The oil insoluble condition of the reaction mass necessarily indicates its water insolubility since the former characteristic invariably occurs subsequent to the latter in phenol-formaldehyde type condensation products. Excepting for the media prepared with tribromophenol, the reactions were terminated by neutralization of the catalyst in the reaction mass with either 50 percent aqueous formic acid or 28 percent aqueous hydrochloric acid. With the :tribromophenol constituent, the evolved hydrogen bromide neutralized the catalyst to obviate the necessity for employing additional acid for the purpose. In the following Table I there is set forth the ingredients and materials that were utilized in each of the products that were prepared as well as the specific gravity of each of the liquid resin syrups that were obtained.

Table II. Light transmitting characteristics of liquid medium "11 e r Percent Wave Length of Light In Angstrom Units Transmission Through Medium Under 5,500 p .0 5,500.. 0 6,000.. 32.5 0,500 7,000.. 50 7,500 61 8,000."... -63 8,500 Q 65 9,000. .67 9,500."... 68 10,000 67.6

As is apparent, the medium had good transmission of light in the infra-red or at least near infra-redrange. A variety of readily available infra-red type photographic films I are quite sensitive to light in this range despite the fact that true infra-red light is' sometimes considered to have a wave length in the range from about 20,000 to 160,000 Angstromunits. f I

By way of further illustration, various pobjects'were photographed on infrared sensitive film throughaone inch thick layer of Medium A usingan ordinary 500 watt flood lamp of the type commonly employed for color Table I.Formulati0ns of various liquid media for well bore photography Approximate Mole Mole Frac- Specific Quantity of Ratio of tion of In- Gravity Medium Ingredients Ingredients Phenolic dividual of Liquid Constituent Ingredi- Resin to Forments Medium aldehyde Tribromophenol 75 g 1 0, 23 Phenfil 25 g- 1 0. 27 2 0 Paraformaldehyde. 15 g 0. 5 Caustic Soda 4 cc 0. 05 Tribromophenol 50 g 0.15 V Ph n l 50 g. 0.53 1 58 Paraformaldehyde. 20 g 0. 67

Caustic Soda 8 00.. 0.038 Tribromophenol 25 g 0.08 on Phenol 0.80 1 31 Paraformaldehyde. 0.83

Caustic Soda 0.025 orthpchloiignlfiernl n Para orma e e D Caustic Soda y 0. 012 26 Formic Acid "2 1%id fit it u Para orma e e E Caustic Soda y 0. 012 37 Formic Acid. 0.017 i art's; ti S 1 iii A: n orma e y e, percen o u F Caustic Soda 5 0. 625

ydrochloric Acid 0.66

When a product was attempted to bemade in the foregoing manner using tribromophenol as the sole phenolic constituent, a solid resinous material was obtained. All of the liquid media were optically clear, and transparent and remained so at room temperature for periods of at least two weeks after their preparation. When maintained at a temperature of about 175 F., all of the liquid media remained fluid and clear for at least about three weeks, although they were observed to become cloudy in less time when cooled from the elevated temperature. The absolute viscosity of each of the liquid products at room temperature was found to be in the range from about 140 to 300 centipoises.

The light transmitting characteristics for light of various wave-lengths of medium A, as determined with a Beckman Model DU Spectrophotometer, are set forth in the following Table II. The test was conducted in the standard way for such evaluations by simply measuring the percentage transmission per wave length through the medium being tested.

photography to provide the illumination. The lamp was spaced about one-half foot from the photographed objects and arranged so as to light them from behind the camera through the liquid medium. Exposures at 0.5 second with lens settings on the camera of f-ll were made. Clear and sharp pictures were obtained in each instance. A representation of an extremely sharp, clear and easily legible photograph of a core section taken in the foregoing manner according to the comprehension of the present invention is schematically reproduced in Figure 2 of the accompanying drawing.

The scope and purview of the present invention is to be interpreted and construed from the context of the hereto appended claims rather than strictly from'the foregoing illustrative specification and description.

What is claimed is 1. Technique for making visual reproductions of sub-.

terraneal objects in wells and the like boring's that pene- 7 is desired a slug of an oil and water immiscible transparent liquid medium having a specific gravity greater than that of water, said transparent liquid medium being an oil and water insoluble liquid condensation product having a specific gravity between about 1.2 and 2 of from about 0.75 to 4 moles of formaldehyde with each unimolar proportion of a phenolic constituent selected from the group consisting of mixtures of tribromophenol and the common, trifunctional phenol, C H OH, that contain mole fractions of at least about 5 percent of the latter; monoand di-brornophenols and their mixtures with common phenol; mono-, diand tri-chlorophenol and their mixtures with common phenol; and mixtures thereof; said liquid slug having a volume equal to that of the portion of the Well bore that encompasses the point at which the visual reproduction is desired; introducing in said well bore and immersing in said medium both a light source for illuminating the object to be visually reproduced and an underliquid operable photographic means; and visually reproducing with said photographing means through said transparent liquid medium the desired object at said point in said boring that is encompassed by and with said liquid medium.

2. The improvement in the art as set forth in claim 1, wherein the liquid condensation product contains from aboutl to 1.5 moles of formaldehyde for each mole of the phenolic constituent therein contained.

3. The improvement in the art as set forth in claim 1, wherein the phenolic constituent in the liquid condensation product is a mixture of tribromophenol and the common phenol. I

4. The improvement in the art as set forth in claim 1, wherein the photographic means is a camera that is adapted to record images on light-sensitive photographic film.

5. The improvement in the art as set forth in claim 1, wherein the photographic means is a camera that is adapted to record images on light-sensitive film and the light source is an incandescent lamp; and wherein the desired object is visually reproduced on a photographic film that is sensitive to infra-red light.

6. The improvement in the art as set forth in claim 1, wherein the photographic means is a televising camera that is adapted to electronically photograph an object and transmit an image to cooperating means for visual reproduction.

References Cited in the file of this patent UNITED STATES PATENTS 2,043,504 Blow June 9, 1936 2,057,146 Heath Oct. 13, 1936 2,812,697 Laval Nov. 12, 1957 

